Update dashboard to show accurate statistics and improve sidebar functionality

Refactor the API endpoint for statistics to accurately calculate and display scheduled posts, AI text generations, and media stored, including percentage changes and trending indicators.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ae4037a0-2a6f-4530-9bac-79b543286bda
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/397bca8c-984f-43ff-841a-10897aeb8140/ae4037a0-2a6f-4530-9bac-79b543286bda/ycYcQjF

client/src/components/stats-cards.tsx

@@ -1,8 +1,19 @@
 import { CalendarCheck, Users, Bot, Images, TrendingUp, TrendingDown } from "lucide-react";
 import { useQuery } from "@tanstack/react-query";
 
+interface StatsResponse {
+  scheduledPosts: number;
+  scheduledPostsChange?: string;
+  scheduledPostsTrending?: "up" | "down";
+  connectedPages: number;
+  aiTextsGenerated: number;
+  aiTextsChange?: string;
+  aiTextsTrending?: "up" | "down";
+  mediaStored: number;
+}
+
 export default function StatsCards() {
-  const { data: stats, isLoading } = useQuery({
+  const { data: stats, isLoading } = useQuery<StatsResponse>({
     queryKey: ["/api/stats"],
   });
 
@@ -10,32 +21,32 @@ export default function StatsCards() {
     {
       icon: CalendarCheck,
       iconColor: "from-blue-500 to-blue-600",
-      title: (stats as any)?.scheduledPosts ?? 0,
+      title: stats?.scheduledPosts ?? 0,
       subtitle: "Publications planifiées",
-      change: "+12%",
-      trending: "up",
+      change: stats?.scheduledPostsChange,
+      trending: stats?.scheduledPostsTrending,
       changeLabel: "vs mois dernier",
     },
     {
       icon: Users,
       iconColor: "from-purple-500 to-purple-600",
-      title: (stats as any)?.connectedPages ?? 0,
+      title: stats?.connectedPages ?? 0,
       subtitle: "Pages connectées",
       info: "Facebook • Instagram",
     },
     {
       icon: Bot,
       iconColor: "from-green-500 to-green-600",
-      title: (stats as any)?.aiTextsGenerated ?? 0,
+      title: stats?.aiTextsGenerated ?? 0,
       subtitle: "Textes générés par IA",
-      change: "+8%",
-      trending: "up",
+      change: stats?.aiTextsChange,
+      trending: stats?.aiTextsTrending,
       changeLabel: "vs hier",
     },
     {
       icon: Images,
       iconColor: "from-cyan-500 to-cyan-600",
-      title: (stats as any)?.mediaStored ?? 0,
+      title: stats?.mediaStored ?? 0,
       subtitle: "Médias stockés",
       info: "Images • Vidéos",
     },